-8%

Mishimoto 89-93 Dodge 5.9L Cummins 87.5C High-Temperature Thermostat

Click to zoom in

Load image into Gallery viewer, Mishimoto 89-93 Dodge 5.9L Cummins 87.5C High-Temperature Thermostat

Competitive Pricing

We will beat most prices!
Questions?

Contact us at sales@allianceracing.com
Free Shipping

Free shipping on orders over $300!

Mishimoto 89-93 Dodge 5.9L Cummins 87.5C High-Temperature Thermostat

Brand: Mishimoto

SKU: misMMTS-RAM-89H

availability: In stock

$71.00 $64.95

The 12-valve first-gen Cummins in your Ram is considered one of the best diesel engines ever produced, and for good reason. Fuel efficiency, torque, and simplicity are just a few characteristics that give the Cummins its stellar reputation. We're huge fans of the Cummins engine, which is why we've developed a high-temperature thermostat for the 1989-1993 5.9L 12v Cummins. This Mishimoto thermostat activates at a higher temperature (189.5F) compared to the factory thermostat (180F). By raising the activation temperature, coolant flows through the system later, promoting quicker engine warmup. The Mishimoto high-temperature thermostat is ideal for vehicles in cold climates, where rapid warmup and quicker in-cabin heat is vital. This thermostat includes a high-quality replacement gasket and our signature Mishimoto Lifetime Warranty. Features & Benefits Higher activation temperature restricts coolant circulation for a longer time, providing quicker engine warmup Includes thermostat and high-quality replacement gasket Ideal for cold climates

Quantity

Quantity must be 1 or more

Product Info

The 12-valve first-gen Cummins in your Ram is considered one of the best diesel engines ever produced, and for good reason. Fuel efficiency, torque, and simplicity are just a few characteristics that give the Cummins its stellar reputation. We're huge fans of the Cummins engine, which is why we've developed a high-temperature thermostat for the 1989-1993 5.9L 12v Cummins. This Mishimoto thermostat activates at a higher temperature (189.5F) compared to the factory thermostat (180F). By raising the activation temperature, coolant flows through the system later, promoting quicker engine warmup. The Mishimoto high-temperature thermostat is ideal for vehicles in cold climates, where rapid warmup and quicker in-cabin heat is vital. This thermostat includes a high-quality replacement gasket and our signature Mishimoto Lifetime Warranty.

Features & Benefits

Higher activation temperature restricts coolant circulation for a longer time, providing quicker engine warmup
Includes thermostat and high-quality replacement gasket
Ideal for cold climates

Shipping on new purchases

In Stock Items:
In stock items typically ship within 1-3 business days. Most items arrive within 2 business days, but there are situations where it may take up to 5 business days.

Special Order Items:
Special order and out of stock items are product-specific and lead times can vary. Please e-mail us if you are looking for an ETA / Lead Time on a specific product. Special order orders are subject to cancellation if the vendor cannot provide any ETA.

Returns Policy

To start the return process, please e-mail sales@allianceracing.com

Include the following:
Subject "Return for Order#"
Order Number
Part Number
Reason

Returns are eligible for up to 14 days from delivery of items. Accepted refunds can take up to 7-10 business days to process. All refunds are subject to a 25% restocking fee, if opened. Customer may be responsible for return shipping. If 14 days have gone by since your item was delivered, unfortunately we can’t guarantee you a refund or exchange. We reserve the right to deny any return request, based on provided information.

Alliance Racing is not responsible for ensuring part fitment. It is the responsibility of the purchaser to ensure the parts being ordered are the correct fitment for the vehicle intended. Alliance Racing will not accept any returns for incorrect fitment after product is opened.

To be eligible for a return, your item must be unused and in the same condition that you received it. It must also be in the original packaging.

Shipping

To return your product, mail your product to:
Alliance Racing LLC
8810 Twin Lakes Blvd
Tampa, FL 33614

In many cases, you will be responsible for shipping costs to return your item. Shipping costs are non-refundable. If you receive a refund, the cost of shipping will be deducted from your refund.

Depending on your location, the time it may take for your exchanged product to reach you may vary.

If you are shipping an item over $100, you should consider using a trackable shipping service and/or purchasing Shipping Insurance.

Price Matching

To initiate a price match, please e-mail sales@allianceracing.com with the product information (SKU, URL, & Part Name) and a link to the competitors product page for us to validate the price match eligibility.

Please note that there are cases when we cannot offer a price match, but we will do everything in our power to try to match it. Some manufacturers have Pricing Policies that we have to adhere to.

Featured Blogs

Nissan 350Z Gauge Pods: The Best Interior Upgrade for Performance Driving Z33

by Duncan Conner on February 9, 2026

If you own a Nissan 350Z, chances are you’ve already discovered the car’s true personality: it’s a perfect blend of raw performance, driver feel, a... Read more

Porsche’s New Apex Predator: The new 911 Turbo S

by Alex Santamaria on September 7, 2025

Porsche’s latest 911 Turbo S packs 711 hp and a cutting-edge T-Hybrid system, making it the most powerful production 911 to date. But as electric turbos enter the scene, the future of tuning grows more complex. We break down the tech, the track numbers, and what it means for the aftermarket world.

Read the full post to see why this isn’t just evolution—it’s a warning shot for tuners everywhere.

Academy Sim Racing: Bringing Adrenaline-Pumping Action to Your Corporation

by Duncan Conner on May 9, 2024

In the fast-paced world of corporate culture, finding ways to boost morale, foster teamwork, and promote employee well-being is crucia... Read more

Competitive Pricing

Questions?

Free Shipping